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THE POPULAR SCIENCE MONTHLY 



recognized, and a keen eye will perceive that Alpha really consists of 

 two stars. They are about six minutes of arc apart, and are of the 

 third and the fourth magnitude respectively. These stars, which to the 

 naked eye appear almost blended into one, really have no physical 

 connection with each other, and are slowly drifting apart. The ancient 

 astronomers make no mention of Giedi being composed of two stars, 

 and the reason is plain, when it is known that in the time of Hippar- 





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Map 2. 



chus, as Flammarion has pointed out, their distance apart was not 

 more than two thirds as great as it is at present, so that the naked eye 

 would not have detected the fact that there were two of them : and 

 it was not until the seventeenth century that they got far enough 

 asunder to begin to be separated by eyes of unusual power. With 



